[FEATURE] Support 3rd party formatters

Grid configuration option "format" needs to be a full
qualified class name since version 0.3.0.

 $TCA['tx_foo_domain_model_bar'] = array(
   'grid' => array(
     'columns' => array(
       'myproperty' => array(
         'format' => 'Foo\\Bar\\Custom\\Vidi\\Formatter\\MyFormatter',
       ),
     ),
   ),
 );

Resolves: #57489
Change-Id: I4be7b9102fda1fd96eaebb6b4af81594d3821a8c